If you are using an Android phone or tablet (Samsung, Google Pixel, Huawei etc.), please follow one of the guides below.
This is the app that MyWork recommends to use for your Microsoft Office 365 email addresses. It provides the best compatibility and most ease of use out of available options for setting up emails on your device.
Please follow this guide on Microsoft's website, following Steps 1 to 3 if you have just installed the app, or Steps 5 to 6 if you already have an email address set up in the app.
Microsoft also provides a "cheat sheet" for using Outlook for Android, which can be downloaded here (PDF).
You may be using the pre-installed Gmail app on your phone. Please follow this guide on Microsoft's website to set up your Office 365 email address/es in this app, following Steps 1 to 6.
If you have a Samsung device and have set up emails before, you would most likely be using the built-in Samsung Email app. Please follow this guide on Microsoft's website, following all of the steps below "Choose your built-in Android email app" (ensuring the "Samsung Email app" tab is selected).